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Confidence HighDec 10, 2025fortinet.com

FortiCloud SSO Authentication Bypass Vulnerabilities Actively Exploited

PatternExternal actor · Hacking · Confidentiality impact

Multiple critical authentication bypass vulnerabilities related to FortiCloud Single Sign-On (SSO) have been actively exploited in Fortinet products. CVE-2026-24858, disclosed in January 2026, allowed malicious actors with a FortiCloud account to log in to devices registered to other users if FortiCloud SSO was enabled. This led to unauthorized firewall configuration changes, account creation, and VPN configuration changes. Earlier, CVE-2025-59718 and CVE-2025-59719 (December 2025) allowed unauthenticated attackers to bypass SSO login via crafted SAML messages. Attacks exploiting these flaws have been observed creating rogue accounts and stealing firewall configuration data.

Signal date
Dec 10, 2025
Updated
Jun 19, 2026
Confidence
High
Sources
2 sources

Signal context

First seen: Dec 10, 2025

Last updated: Jun 19, 2026

Status: Public signal

Key points

  • CVE-2026-24858: Authentication bypass allowing unauthorized access to FortiOS, FortiManager, FortiWeb, FortiProxy, and FortiAnalyzer devices with FortiCloud SSO enabled.
  • Exploitation led to unauthorized firewall configuration changes, account creation, and VPN configuration changes.
  • CVE-2025-59718 and CVE-2025-59719: Improper verification of cryptographic signatures allowing SSO bypass via crafted SAML messages in FortiOS, FortiProxy, FortiSwitchManager, and FortiWeb.

Signal analysis

Beta

It helps compare this signal with other published signals without treating the labels as final determinations.

Affected organization
Fortinet logo
Fortinet

Likely country: Location not provided

Threat source
Hacking activity

Watch internet-facing systems, credential abuse and exploit activity.

  • Source type: outside the affected organization
Business impact
Potential data exposure

Impact area: Confidentiality

Likely asset: User or customer data

Trend context
17 signals with similar action pattern
  • 1 signal in the same sector
  • 22 signals with the same likely impact area
  • 3 signals linked to this organization/domain
Mentioned entities
FortinetData DisclosureFortiCloud SSO Authentication Bypass VulnerabilitiesActively Exploited MultipleFortiCloud Single Sign-OnSSOFortinetCVE-2026-24858FortiCloudFortiCloud SSO

External sources

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